• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.168-169
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• 2015

SMART Frame is a composite precast concrete structure system to deliver the advantages of both steel frame and reinforced concrete. Many studies have established to date that SMART Frame is more advantageous than conventional frame-type structure in terms of structural stability, constructability, economic viability as well as reduction of construction schedule. However, such studies have focused primarily on wall-type or flat slab-type apartment housing structures, failing to include Rahmen structures in their scope. Accordingly, this study aims to analyze the benefits of potential application of SMART Frame to RC Rahmen structures. As the structural stability and constructability of SMART Frame is already proven, this study reviews its benefits from the perspective of cost reduction. Conclusion of this study will be used subsequently in predicting the benefits of SMART Frame when it is adapted to RC Rahmen structures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.139-140
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• 2011

The government encourages adoption of Rahmen structure design to ensure efficient management of national resources. However, in comparison with bearing-wall structure, Rahmen structure requires higher unit construction cost and present challenges in terms of securing adequate floor area ratio and floor height. That is why project clients have been disinterested in adoption of Rahmen structure design. Therefore, we have attempted to find factors having influence on decline of project viability for Rahmen structure. This study will be utilized as a basic reference study for promotion of Green Frame design which is a composite PC structure already developed.

• Land and Housing Review
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• v.5 no.2
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• pp.107-114
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• 2014

Passive energy dissipation systems for seismic applications have been under development for a number of years with a rapid increase in implementations starting in the mid-1990s in many countries. A metallic hysteretic damper has most commonly been used for seismic protection of structures in domestic area because they present high energy-dissipation potential at relatively low cost and easy to install and maintain. This paper presents an analytical case study of the effectiveness of isotropic hysteretic metallic damper(IHMD) called Kagome as a passive dissipative device in reducing structural response during seismic excitation. An eighteen-story RC framed apartment building is studied with and without IHMD. Results demonstrate the feasibility of these techniques for seismic mitigation. The inclusion of supplemental passive energy dissipation devices in the form of IHMD proved to be a very effective method for significantly reducing the seismic response of the building investigated.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.23-34
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• 2015

Recently a new damper system with Kogome truss structure was developed and its mechanical properties were verified based on the laboratory test. This paper presents a Kagome truss damper external connection method for seismic strengthening of RC frame structural system. The Kagome external connection method, proposed in this study, consisted of building structure, Kagome damper and support system. The method is capable of reducing earthquake energy on the basis of the dynamic interaction between external support and building structures using Kagome damper. The pseudo-dynamic test, designed using a existing RC frame apartment for pilot application of LH corporation, was carried out in order to verify the seismic strengthening effects of the proposed method in terms of the maximum load carrying capacity and response ductility. Test results revealed that the proposed Kagome damper method installed in RC frame enhanced conspicuously the strength and displacement capacities, and the method can resist markedly under the large scaled earthquake intensity level.

• Korean Journal of Construction Engineering and Management
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• v.23 no.2
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• pp.95-101
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• 2022

This study attempts to identify the ways of reducing the floor impact sound, by applying six different types of the reinforced bar girders and stirrup arrangements to the Structure: (1) the longer-direction girder arrangements (2) the shorter-direction girder arrangements (3) the diagonal-direction arrangements (4) the longer-direction girder arrangements with stirrups (5) the shorter-direction girder arrangements with stirrups (6) the diagonal-direction arrangements with stirrups. In order to identify the most effective structural changes, each slab was tested with bang machines, measuring the level of the sound impact. The results showed that the longer-direction girder arrangements with stirrups were the most effective one. In addition, the effectiveness of slab was found to be remarkable, showing the level of minimum 1dB to maximum 5dB, where the slab was compared with the control models without girders and stirrups. In conclusion, it is suggested that the longer-direction girder arrangements with stirrups could possibly be applied to the Wall Structures to minimize the floor impact sound.

• Journal of Korean Society of Steel Construction
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• v.25 no.1
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• pp.1-13
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• 2013

Most rahmen-type temporary bridges are constructed with limited bridge length to prevent excessive horizontal forces due to the thermal expansion of main girder. To achieve a long length temporary bridge several independent bridges are required and they can not share the bents, at the rahmen-type ends, with the adjacent ones. The additional bents require more cost and reduce the section space under bridges. In order to remove extra bents with keeping the rahmen effect at the bridge ends, this study proposes a new rahmen-type movable joint system for temporary bridges.

• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.611-620
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• 2007

The beam-column connection is the critical design section of general steel frame structures owing to the behavioral characteristics of the structural system. As most members of a frame structure are composed of rolled section beams, the cross-section of the beam members is governed by the negative bending moment near beam-column connections. Such a design concept leaves a redundant load-carrying capacity at the positive bending regions of the beam members leading to design inefficiency. Therefore, it is of utmost importance to redistribute the beam end moments and reduce the stresses at the beam-column connections for a more efficient design of steel frame structures. In this study, reaction-moment prestressing method (RMPM) was proposed for the innovative design and construction of steel frame structures. The RMPM is a prestressing method utilizing the elastic bending deformation of a beam member induced by temporary prestressing for the distribution of a relatively large bending moment to other sections for the efficient use of the beam section. By the application of the RMPM, the negative bending moment at the beam-column connections can be significantly reduced, ultimately leading to possible use of smaller beam sections. Through a series of model tests and numerical analyses of steel frame structures, the moment distributing effect and feasibility of the RMPM was verified.

• Explosives and Blasting
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• v.28 no.2
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• pp.99-107
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• 2010

Domestic explosive demolition techniques have been developed and applied for low-rise structures up to now. However, the demand for the development of those techniques that can be applied economically, safely and environment-friendly rapidly increases because the old high-rise RC rahmen structures that were built since around 1970s are now required to rebuild. As a result, element technologies of explosive demolition for low-rise structures were applied to take advantage of technology in high-rise structures that performed application testing at Chungang Department demolition field in Daejeon city. It could judge elements technology establishment for high-rise structure demolition and field application and suggest the improvements when the problems occurred to develop High-rise building demolition techniques for method of protection a field test and the dust reduction test. The water cannon test was applied to reduce the dust site and the drilling tests are performed to select the best components for explosives demolition elements techniques of the reliability. This paper shows that we have the ability to remove a high-rise building using environmentally friendly safe and economical explosives demolition method. It would contribute to prevent a foreign company from entering the domestic market and should contribute to acquire competitiveness of domestic demolition industry.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.565-575
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• 1998

This study presents overall process for designing and constructing a prestressed frame overpass using temporary piers. For the purpose of automating the design process, this study presents a computer program. According to the effective span(20m, 25m, 30m, 35m, 40m, 45m), this study performed parametric analysis and eventually presented appropriate cross section and compared this cross section with that of the existing simple steel overpass in girder height and quantify of the steel. $26{\sim}48%$ for gilder height and $25{\sim}34%$ for quantify of the steel are reduced as the result of study for span length $20{\sim}45m$. As long as the span length. the reduction rate was large.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.87-98
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• 2007

Generally, main girders and steel piers of temporary bridges form the steel rahmen structure. In this study, the rational stability design procedure for main members of temporary bridges was presented using a 3D system buckling analysis and second-order elastic analysis. Six types of temporary bridges, which can be designed and fabricated in reality, were chosen and the buckling design for them was performed in consideration ofload combinations of dead and live loads, thermal load, and wind load. Effective buckling length of steel piers, transition of 3D buckling modes, and effects of second-order analysis were investigated through a case study involving six temporary bridges.